Increasing Security With Pacific Lock Hidden Shackle Hockey-Puck Padlocks

Feb. 2, 2012
The diameter and position of the shackle prevent unauthorized entry from pulling the cylinder, core or plug.

“Hockey-puck” style padlocks have become very popular because of their mass, hidden shackle, keying options and the higher level of actual and perceived security. This highly adaptable style of padlock is being used to secure standard padlock and hasp applications as well as vehicle doors, box truck roll up shutter style doors, trailer doors, trash bins and gates. Unlike a conventional padlock, the lock cylinder is almost always in the sideways or downward fixed position, making it more difficult to gain access to the keyway.

This type of padlock uses a large diameter rod style of shackle compared to a conventional padlock shackle. The rod style shackle rotates as the key is turned. The shackle tip is machined to an oval tip with a slot running the circumference. The body of the “hockey-puck” padlock has a machined circular opening at the top. Hardened rods create the receptacle for the shackle tip. The shackle tip enters the opening when the lock cylinder is in the unlocked condition.

To lock the padlock once the shackle is in the closed position, the plug is rotated 90 degrees with the slot in the shackle rotating around the two hardened pins. In the locked condition, the shackle oval tip is 90 degrees out of position to the rectangular opening in the body. The diameter and position of the shackle eliminate many methods of unauthorized entry including pulling the cylinder, core or plug.

The “hockey-puck” body shape can accommodate different surfaces, having the standard option of a flat or stepped back. When first introduced, the 2-7/8” “hockey-puck” padlock was equipped with a standard five pin tumbler padlock keyway lock cylinder. At this time, there are two standard widths available; 2-7/8” and 3” wide bodies. Note: The 3” wide body padlocks will not fit into hasps made for the 2-7/8” wide body padlocks.

Keying options for these hidden shackle padlocks range from the manufacturers’ six pin tumbler cylinder having a padlock keyway to conventional six pin tumbler K-I-K/K-I-L lock cylinders and small format interchangeable cores (SFIC). The conventional lock cylinder and SFIC are available in the larger 3” width body.

 “Hockey-puck” padlock hasps are made of heavy gauge metal, designed to resist removal using a pry bar or similar tools. The stepped back version can accommodate some of the conventional padlock hasps without providing sufficient surface area beneath the padlock body.

For this article, we will discuss the Pacific Lock “Hockey-Puck” Padlocks that include the conventional industry standard 2-7/8” body width, and the SFIC and K-I-K/K-I-L models having the 3” body width. The additional width is necessary to accommodate the conventional cylinder and the interchangeable core patent pending sleeve assembly. All of the Pacific Lock “hockey-puck” padlocks are equipped with a 13/32” diameter shackle.

PACLOCK 2-7/8” body width “hockey-puck” padlocks are manufactured of solid steel and hardened. They are equipped with a six pin tumbler lock having the KB6-P0 keyway. The “hockey-puck” padlocks are rekeyable to competitive padlock cylinders including the four pin tumbler.

Note: All PACLOCK 400 Series hockey-puck padlocks have a stepped back to accommodate conventional padlock hasps. All PACLOCK 2170 Series have an entirely flat back.

The 400XIC and the 2170XIC are the 3” body width “hockey-puck” padlocks that accommodate conventional six pin tumbler standard and high security lock cylinders and the six or seven pin tumbler SFICs from lock and core manufacturers including Schlage®, Best®, Falcon®, Arrow®, KSP®, Kaba Ilco®, etc. Contact Pacific Lock for specific applications.

In order to accommodate the conventional lock cylinder and the interchangeable core, Pacific Lock developed their patent pending X and IC sleeve assemblies. The X sleeve assembly is used with conventional K-I-K/K-I-L lock cylinders and the IC sleeve assembly is used with the SFIC. These sleeves are the same overall size permitting them to be installed in the 400XIC and 2170XIC three inch body width “hockey-puck” padlocks. The sleeve assemblies are manufactured of chrome plated brass. They are not interchangeable as the X sleeve has a larger opening than the IC sleeve.

The X and IC sleeve assemblies contain specialized parts to accommodate a cylinder or a SFIC. The shackle component for the SFIC has two fingers that slide into the rear of the core’s plug. The fingers transfer the operation from the plug to the lock mechanism. A special washer is inserted into the sleeve secures the shackle in place.

The IC sleeve assembly comes complete. To install the sleeve into the padlock, loosen the 2.5 mm diameter setscrew. Insert the IC sleeve assembly and tighten enough to secure the sleeve, permitting it to slide within the padlock body.

The control key retracts the lug, permitting the core to slide into the IC sleeve. Once inserted, extending the lug and removing the control key secures the core. The padlock is now operable.

The X sleeve assembly contains a driver that replaces the existing lock cylinder driver. The X sleeve driver is sized to mate with the shackle. Several different drivers accommodate the lock cylinder manufacturer. The shackle has a slot at the front into which the driver slides. The shackle is slid into the X sleeve assembly and the stopper slid on top.

The barrel plug slides over the bible of the cylinder and secures the cylinder into the X sleeve. The driver is installed and the barrel plug covers the bible, the cylinder is slid into the sleeve. The Phillips head screw secures the cylinder. The X sleeve assembly is inserted to the padlock and secured using a 2.5 mm diameter setscrew. The padlock is now operable.

400XIC and 2170XIC hockey-puck padlocks and sleeve assemblies are sold separately.

As the demand for hidden shackle locking systems increases, so will the need for new designs to support the applications.  Starting in 2012, Pacific Lock will have the ability to manufacture short run, custom jobs where unusual padlock designs are commonplace. 

For more information, contact PACLOCK, 25615 Hercules St., Valencia, CA 91355. Telephone: 661-294-3707. Web Site:

To read additional Locksmith Ledger articles on Pacific Lock products, visit